Abstract

Single crystals of bismuthtitanate (BiT) and lanthanum-substituted BiT (BLT)] were grown by a self-flux method. BLT showed a smaller remanent polarization along the axis of than for BiT, which mainly originates in its smaller ionic displacements along the a axis. Striped 90° domain walls as well as head-to-head and tail-to-tail 180° domain walls were observed for both crystals, and La substitution led to a marked decrease in the 90° domain width from 8.5 μm (BiT) to 2.5 μm for BLT Piezoelectric-force microscope observations suggested that antiphase domain boundary (ADB) is present only for BLT and the ADB plays an important role in the formation of the 90° domain.